summaryrefslogtreecommitdiff
path: root/gdbus/watch.c
blob: 7d7853fc8ac1b550e0c88bf81c42f24fa42a75d6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
/*
 *
 *  D-Bus helper library
 *
 *  Copyright (C) 2004-2009  Marcel Holtmann <marcel@holtmann.org>
 *
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <string.h>

#include <glib.h>
#include <dbus/dbus.h>

#include "gdbus.h"

#define info(fmt...)
#define error(fmt...)
#define debug(fmt...)

static DBusHandlerResult name_exit_filter(DBusConnection *connection,
					DBusMessage *message, void *user_data);

static guint listener_id = 0;
static GSList *name_listeners = NULL;

struct name_callback {
	GDBusWatchFunction conn_func;
	GDBusWatchFunction disc_func;
	void *user_data;
	guint id;
};

struct name_data {
	DBusConnection *connection;
	char *name;
	GSList *callbacks;
};

static struct name_data *name_data_find(DBusConnection *connection,
							const char *name)
{
	GSList *current;

	for (current = name_listeners;
			current != NULL; current = current->next) {
		struct name_data *data = current->data;

		if (connection != data->connection)
			continue;

		if (name == NULL || g_str_equal(name, data->name))
			return data;
	}

	return NULL;
}

static struct name_callback *name_callback_find(GSList *callbacks, guint id)
{
	GSList *current;

	for (current = callbacks; current != NULL; current = current->next) {
		struct name_callback *cb = current->data;
		if (cb->id == id)
			return cb;
	}

	return NULL;
}

static void name_data_call_and_free(struct name_data *data)
{
	GSList *l;

	for (l = data->callbacks; l != NULL; l = l->next) {
		struct name_callback *cb = l->data;
		if (cb->disc_func)
			cb->disc_func(data->connection, cb->user_data);
		g_free(cb);
	}

	g_slist_free(data->callbacks);
	g_free(data->name);
	g_free(data);
}

static void name_data_free(struct name_data *data)
{
	GSList *l;

	for (l = data->callbacks; l != NULL; l = l->next)
		g_free(l->data);

	g_slist_free(data->callbacks);
	g_free(data->name);
	g_free(data);
}

static int name_data_add(DBusConnection *connection, const char *name,
						GDBusWatchFunction connect,
						GDBusWatchFunction disconnect,
						void *user_data, guint id)
{
	int first = 1;
	struct name_data *data = NULL;
	struct name_callback *cb = NULL;

	cb = g_new(struct name_callback, 1);

	cb->conn_func = connect;
	cb->disc_func = disconnect;
	cb->user_data = user_data;
	cb->id = id;

	data = name_data_find(connection, name);
	if (data) {
		first = 0;
		goto done;
	}

	data = g_new0(struct name_data, 1);

	data->connection = connection;
	data->name = g_strdup(name);

	name_listeners = g_slist_append(name_listeners, data);

done:
	data->callbacks = g_slist_append(data->callbacks, cb);
	return first;
}

static void name_data_remove(DBusConnection *connection,
					const char *name, guint id)
{
	struct name_data *data;
	struct name_callback *cb = NULL;

	data = name_data_find(connection, name);
	if (!data)
		return;

	cb = name_callback_find(data->callbacks, id);
	if (cb) {
		data->callbacks = g_slist_remove(data->callbacks, cb);
		g_free(cb);
	}

	if (data->callbacks)
		return;

	name_listeners = g_slist_remove(name_listeners, data);
	name_data_free(data);

	/* Remove filter if there are no listeners left for the connection */
	data = name_data_find(connection, NULL);
	if (!data)
		dbus_connection_remove_filter(connection,
						name_exit_filter,
						NULL);
}

static gboolean add_match(DBusConnection *connection, const char *name)
{
	DBusError err;
	char match_string[128];

	snprintf(match_string, sizeof(match_string),
			"interface=%s,member=NameOwnerChanged,arg0=%s",
			DBUS_INTERFACE_DBUS, name);

	dbus_error_init(&err);

	dbus_bus_add_match(connection, match_string, &err);

	if (dbus_error_is_set(&err)) {
		error("Adding match rule \"%s\" failed: %s", match_string,
				err.message);
		dbus_error_free(&err);
		return FALSE;
	}

	return TRUE;
}

static gboolean remove_match(DBusConnection *connection, const char *name)
{
	DBusError err;
	char match_string[128];

	snprintf(match_string, sizeof(match_string),
			"interface=%s,member=NameOwnerChanged,arg0=%s",
			DBUS_INTERFACE_DBUS, name);

	dbus_error_init(&err);

	dbus_bus_remove_match(connection, match_string, &err);

	if (dbus_error_is_set(&err)) {
		error("Removing owner match rule for %s failed: %s",
				name, err.message);
		dbus_error_free(&err);
		return FALSE;
	}

	return TRUE;
}

static DBusHandlerResult name_exit_filter(DBusConnection *connection,
					DBusMessage *message, void *user_data)
{
	GSList *l;
	struct name_data *data;
	char *name, *old, *new;
	int keep = 0;

	if (!dbus_message_is_signal(message, DBUS_INTERFACE_DBUS,
							"NameOwnerChanged"))
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

	if (!dbus_message_get_args(message, NULL,
				DBUS_TYPE_STRING, &name,
				DBUS_TYPE_STRING, &old,
				DBUS_TYPE_STRING, &new,
				DBUS_TYPE_INVALID)) {
		error("Invalid arguments for NameOwnerChanged signal");
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
	}

	data = name_data_find(connection, name);
	if (!data) {
		error("Got NameOwnerChanged signal for %s which has no listeners", name);
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
	}

	for (l = data->callbacks; l != NULL; l = l->next) {
		struct name_callback *cb = l->data;
		if (*new == '\0') {
			if (cb->disc_func)
				cb->disc_func(connection, cb->user_data);
		} else {
			if (cb->conn_func)
				cb->conn_func(connection, cb->user_data);
		}
		if (cb->conn_func && cb->disc_func)
			keep = 1;
	}

	if (keep)
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

	name_listeners = g_slist_remove(name_listeners, data);
	name_data_free(data);

	/* Remove filter if there no listener left for the connection */
	data = name_data_find(connection, NULL);
	if (!data)
		dbus_connection_remove_filter(connection, name_exit_filter,
						NULL);

	remove_match(connection, name);

	return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

guint g_dbus_add_service_watch(DBusConnection *connection, const char *name,
				GDBusWatchFunction connect,
				GDBusWatchFunction disconnect,
				void *user_data, GDBusDestroyFunction destroy)
{
	int first;

	if (!name_data_find(connection, NULL)) {
		if (!dbus_connection_add_filter(connection,
					name_exit_filter, NULL, NULL)) {
			error("dbus_connection_add_filter() failed");
			return 0;
		}
	}

	listener_id++;
	first = name_data_add(connection, name, connect, disconnect,
						user_data, listener_id);
	/* The filter is already added if this is not the first callback
	 * registration for the name */
	if (!first)
		return listener_id;

	if (name) {
		debug("name_listener_add(%s)", name);

		if (!add_match(connection, name)) {
			name_data_remove(connection, name, listener_id);
			return 0;
		}
	}

	return listener_id;
}

guint g_dbus_add_disconnect_watch(DBusConnection *connection, const char *name,
				GDBusWatchFunction func,
				void *user_data, GDBusDestroyFunction destroy)
{
	return g_dbus_add_service_watch(connection, name, NULL, func,
							user_data, destroy);
}

guint g_dbus_add_signal_watch(DBusConnection *connection,
				const char *rule, GDBusSignalFunction function,
				void *user_data, GDBusDestroyFunction destroy)
{
	return 0;
}

gboolean g_dbus_remove_watch(DBusConnection *connection, guint id)
{
	struct name_data *data;
	struct name_callback *cb;
	GSList *ldata, *lcb;

	if (id == 0)
		return FALSE;

	for (ldata = name_listeners; ldata; ldata = ldata->next) {
		data = ldata->data;
		for (lcb = data->callbacks; lcb; lcb = lcb->next) {
			cb = lcb->data;
			if (cb->id == id)
				goto remove;
		}
	}

	return FALSE;

remove:
	data->callbacks = g_slist_remove(data->callbacks, cb);
	g_free(cb);

	/* Don't remove the filter if other callbacks exist */
	if (data->callbacks)
		return TRUE;

	if (data->name) {
		if (!remove_match(data->connection, data->name))
			return FALSE;
	}

	name_listeners = g_slist_remove(name_listeners, data);
	name_data_free(data);

	/* Remove filter if there are no listeners left for the connection */
	data = name_data_find(connection, NULL);
	if (!data)
		dbus_connection_remove_filter(connection, name_exit_filter,
						NULL);

	return TRUE;
}

void g_dbus_remove_all_watches(DBusConnection *connection)
{
	struct name_data *data;

	while ((data = name_data_find(connection, NULL))) {
		name_listeners = g_slist_remove(name_listeners, data);
		name_data_call_and_free(data);
	}

	dbus_connection_remove_filter(connection, name_exit_filter, NULL);
}